The thing is that velocity is relative (that's not the same relative as in special theory of relativity, this kind of relative was discovered by Galileo long before Einstein). The whole concept of "the velocity of the ship" makes no sense, you need something to use as a reference. If we are driving side by side on the motorway, then my velocity with respect to you is 0 km/h, but at the exact same time my velocity relative to the road may be 100 km/h. And on board of the car, I have no way of telling whether I'm going 100 km/h or 200 km/h except by looking at some reference that I will (arbitrarily) declare to be at a standstill.

Acceleration is different: I can measure whether I'm accelerating without looking at an external reference, for example by hanging something on a wire from the ceiling of my car. If I push down the accelerator, the object will swing backwards, and stay angled backwards until I stop accelerating and get to a constant speed again. An elevator is an even better example: you can clearly feel the acceleration when it starts moving, you don't notice a thing while it's moving, but then you feel it decelerate again. This is all Newtonian mechanics, you don't need Einstein for this.

What Special Relativity says is that as your speed with respect to an observer increases, that observer will measure various properties of you and your ship differently from how you measure them on board. For example, the observer will think that your clocks are running slow and that you're squashed together in the direction of travel, but you won't notice a thing. In fact, if you look back at that observer, then you would say that his clock was running slow, and that he is the one that's squashed together. After all, if you are moving at high speed relative to him, then he is moving at high speed relative to you, too!

One other funny thing that you will both measure is that the other party will appear to react too sluggishly to an accelerating force. Let's say the observer knows the mass of your ship, and how powerful your rocket engine is, and he sees you firing your engine. He can calculate how quickly that should accelerate you by Newton's law: a = F / m, where F in the force applied by the rocket, and m your mass. If he actually looks at you zipping by and measures your acceleration however, he will find that your real acceleration appears to be much lower. The tendency of objects to resist acceleration is called (inertial) mass, and so the observer concludes that your mass is larger than he thought it was.

The key insight of Special Relativity is that space and time are linked together, and that observers that move relative to each other will measure the same quantity (e.g. the length of your ship) to have a different value. It's a sort of perspective trick: if we both got out of our cars some way from each other, then I would say that my car appears bigger (since it's closer to me), and you would say that your car appears bigger (since it's closer to you). Of course, it's impossible for both cars to be bigger than the other one, just like it's impossible for your space ship to have two different lengths at the same time. And it doesn't, it just that measurements done in different frames of reference yield different results if those frames of reference are moving with respect to each other.

_________________Say, can you feel the thunder in the air? Just like the moment ’fore it hits – then it’s everywhereWhat is this spell we’re under, do you care? The might to rise above it is now within your sphereMachinae Supremacy – Sid Icarus

My explanation of relativity:there are three objects in space, positioned:a b c in a straight line.

b is ten miles away from a, and c is ten miles away from b.b is moving towards a, and will reach a in an hour. c is moving toward a at the same speed. From the perspective of a, b is going at ten miles and hour, because it will take b one hour to cover the 10 miles to a. From the point of view of a, c is also moving at ten miles per hour, since it will take c 2 hours to reach a from twenty miles away.But c will never reach b, because they are both traveling at the same speed. So from b's point of view, c isn't moving at all!

Here's where Einstein comes in. If a particle of light, a photon, starts from where c is, and travels towards a and b, and a records the time that it takes for that photon to reach a, and b records the time it takes the photon to reach b, and then they calculate the speed of the photon using those numbers, the speed of the photon will be exactly the same for both b and a! That speed is approximately 186,282 miles per second (thank you, wikipedia). Instead of the speed of light changing (being relative), time itself is measured differently by b, and a!

_________________“Once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return.” -Anonymous

isnt time only messured by us tho on the rate of our planets revolving speed tides and rotation therefore how would that be relavent in other parts where a day could be a year and so forth im talking start from blank not with what we know is real here 500,000 miles from earth cant ring aa if out of fuel so would we not need to look more at collecting what we have out there to get back

isnt time only messured by us tho on the rate of our planets revolving speed tides and rotation therefore how would that be relavent in other parts where a day could be a year and so forth im talking start from blank not with what we know is real here 500,000 miles from earth cant ring aa if out of fuel so would we not need to look more at collecting what we have out there to get back

We measure time accurately on earth using atomic clocks. An atomic clock moved to a planet elsewhere would still show the same decay rate to the observer.

Not quite sure what you are on about in the rest of you message. Punctuation would help understanding I think.

dont do punctuation lol to much goes on in my head to worry about dots on paper lol to get a start from fresh we need to imagin earth does not exsist cuz if you run out of fuel up there cant call a breakdown truck so need a form of trvel and fuel ready and available anywhere in space or we can forget going to far at all need to start with no planet time is erelavent and go back to basics like solar power and what we have out there most look what we have on earth and how far we can go

Puntuation and coherent sentences are critical to effective communication between humans. You can have as much as you want going on in your head but if you suck at communicating with other people, it will remain in your head. No benefit to anyone, not even yourself.

...from the point of view of an observer standing on the sun. You cannot make such statements without specifying an observer.

There is another effect though that you may be thinking of, which is that clocks run more slowly in a gravitational field, because space-time gets warped there (according to General Relativity, Special Relativity assumes a flat space-time, which is why it's special, it only takes into account that one special case). So, if two observers were moving at the same speed in the same direction, but one of them was closer to a star or planet, then his clock would run more slowly. Both observers would agree on this.

I'm not sure about Earth vs. Mercury, Earth has a stronger gravitational field (i.e. it's heavier), but Mercury is much closer to the Sun. No idea who wins .

_________________Say, can you feel the thunder in the air? Just like the moment ’fore it hits – then it’s everywhereWhat is this spell we’re under, do you care? The might to rise above it is now within your sphereMachinae Supremacy – Sid Icarus

dont do punctuation lol to much goes on in my head to worry about dots on paper lol to get a start from fresh we need to imagin earth does not exsist cuz if you run out of fuel up there cant call a breakdown truck so need a form of trvel and fuel ready and available anywhere in space or we can forget going to far at all need to start with no planet time is erelavent and go back to basics like solar power and what we have out there most look what we have on earth and how far we can go

I would suggest then that you type your responses in to an word processor of some description and use the spell and grammar checker to help you out. That should help those trying to read your messages, and doesn't take very much more time.